Fastener having improved-load carrying capacity

ABSTRACT

A fastener for substantially rigidly interengaging two members. The fastener includes a stud element adapted to extend through an opening in one of the members and having a cam slot adapted to engage a pin on the other of the members. A stud element is rotatable between an open and closed position on the pin. A housing surrounds the upper portion of the stud element in rotatable relationship therewith and is positioned on one side of the surface of the one member distal from the other member when the cam slot is engaged with the pin. The housing has surfaces thereon forming a slot in the wall thereof inclined with respect to the transverse axis of the housing. A bar extends laterally from the stud element through the slot and engages the slot forming surface of the housing. The housing has an upper rim and a lower rim and the slot in the wall of the housing extends through at least one rim thereof so as to interrupt the exterior surface of said rim and to facilitate insertion and removal of the bar with respect to the slot. Means are provided for retaining the bar in the slot so that when the pin is in the closed position in the cam slot and the housing or stud are rotated relative to one another, the bar will shift in the slot from a relaxed position to a locked position and will be supported by a portion of the slot forming surfaces while in the locked position to thereby increase the load carrying capacity of the fastener.

United States Patent Gunther [54] FASTENER HAVING IMPROVED-LOAD CARRYINGCAPACITY [72] Inventor: Conrad J. Gunther, Uniondale,

[73] Assignee: Dzus Fastener Co., Inc., West lslip, NY.

[22] Filed: March 24, 1971 [21] Appl. No.: 127,604

Related US. Application Data [63] Continuation-impart of Ser. No.866,698, Oct.

19, 1969, Pat. No. 3,594,876.

[52] US. Cl. ..24/221 A [51] Int. Cl. ..A44b 17/00 [58] Field of Search..24/22l K, 221 A, 221 R [56] References Cited UNITED STATES PATENTS3,152,822 10/1964 Griffiths ..24/221 K 3,222,744 12/1965 Dellith..24/221 A FOREIGN PATENTS OR APPLICATIONS 637,697 5/1950 Great Britain..24/221 A Primary Examiner-Bernard A. Gelak Att0rneyKane, Dalsimer,Kane, Sullivan & Kurucz [5 7] ABSTRACT A fastener for substantiallyrigidly interengaging two members. The fastener includes a stud elementadapted to extend through an opening in one of the members and having acam slot adapted to engage a pin on the other of the members. A studelement is rotatable between an open and closed position on the pin. Ahousing surrounds the upper portion of the stud element in rotatablerelationship therewith and is positioned on one side of the surface ofthe one member distal from the other member when the cam slot is engagedwith the pin. The housing has surfaces thereon forming a slot in thewall thereof inclined with respect to the transverse axis of thehousing. A bar extends laterally from the stud element through the slotand engages the slot forming surface of the housing. The

. housing has an upper rim and a lower rim and the slot in the wall ofthe housing extends through at least one rim thereof so as to interruptthe exterior surface of said rim and to facilitate insertion and removalof the bar with respect to the slot. Means are provided for retainingthe bar in the slot so that when the pin is in the closed position inthe cam slot and the housing or stud are rotated relative to oneanother, the bar will shift in the slot from a relaxed position to alocked position and will be supported by a portion of the slot formingsurfaces while in the locked position to thereby increase the loadcarrying capacity of the fastener.

P'A'TENTEBSEP 5 m2 3,688,352

... :lmlmm g INVENTOR TTORNEYS FASTENER HAVING IMPROVED-LOAD CARRYINGCAPACITY CROSS-REFERENCE TO RELATED APPLICATION This application is acontinuation-in-part of application Ser. No. 866,698, filed Oct. 19,1969, now U.S. Pat. No. 3,594,876 and incorporates by reference all ofthe subject matter contained therein.

BACKGROUND OF THE INVENTION The load-carrying capacity of fasteningdevices similar to those shown in Dzus U.S. Pat. No. 2,337,457, isgenerally limited by the capacity of the spring which urges the couplingelements into engagement. The force exerted on the panel mounted pin bythe stud element is limited by the size of the spring interposed betweenthe pin and stud element. For many applications, this is quiteacceptable, however, there are certain instances where it is desirableto have a more rigid fastening member and one which will withstandgreater loads.

Furthermore, under certain circumstances, the attached panels may becomeexposed to excessive vibration and when common types of spring loadedfasteners such as those described in the above mentioned patent areemployed, excessive wear may occur on the panels at the point ofattachment. This excessive wear has a deleterious effect on the attachedpanel arrangement such that the panels may become loose or damaged inother ways. Naturally, this is extremely undesirable in the art and,therefore, under the circumstances discussed above, a fastener whichwould specifically overcome the discussed problems would be extremelyadvantageous.

It should also be kept in mind that a fastener of the desired typeshould be constructed so as to be easily manufactured and assembled.Naturally, the design should not detract from the strength and operationof the fastener.

SUMMARY OF THE INVENTION With the above in mind, among the primaryobjectives of the invention are to provide a fastener assembly capableof handling increased loads placed upon panels or other members joinedby the fastener, and which will prevent excessive wear about the pointthrough which it is inserted in a panel subjected to a large amount ofvibration. Additionally, the fastener is of a design which facilitatesmanufacture and assembly thereof without detracting from the previouslymentioned objectives of the design. Consequently, a more economicalfastener is provided to accomplish the desired results.

The fastener is designed for substantially rigidly interengaging twomembers. The fastener includes a stud element adapted to extend throughan opening in one of the members and has a cam slot adapted to engage apin on the other of the members. A stud element is rotatable between anopen and closed position on the pin. A housing surrounds the upperportion of the stud element in rotatable relationship therewith and ispositioned on one side of the surface of the one member distal from theother member when the cam slot is engaged with the pin. The housing hassurfaces thereon forming a slot in the wall thereof inclined withrespect to the transverse axis of the housing. A bar extends laterallyfrom the stud element through the slot and engages the slot formingsurface of the housing. The housing has an upper and a lower rim and theslot in the wall of the housing extends through at least one rim thereofso as to interrupt the exterior surface of the rim and to facilitateinsertion and removal of the bar with respect to the slot. Means areprovided for retaining the bar in the slot so that when the pin is inthe closed position in the cam slot and the housing or stud are rotatedrelative to one another, the bar will shift in the slot from a relaxedposition to a locked position and will be supported by a portion of theslot forming surfaces while in the locked position to thereby increasethe load-carrying capacity of the fastener.

With the above comments in mind, reference is had to the attacheddrawings.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings:

FIG. 1 is a vertical sectional view of the fastener with the support barrotated into a locked position;

FIG. 2 is a top sectional view thereof taken along the plane of line 22of FIG. 1; and

FIG. 3 is a partially sectional exploded perspective view of thefastener.

DESCRIPTION OF THE PREFERRED EMBODIMENT Initially turning to FIG. 1 ofthe drawing, the fastener is shown in a disassembled explodedrelationship. Housing 10 is provided with a pair of diametricallyopposed inclined slots 11 and 11a. The number of slots employed for aparticular fastener housing is a matter of choice, for example such as1, 2 or 4. For exemplary purposes, a fastener having two diametricallyopposed slots is shown in the embodiment described herein.

Each slot is inclined upwardly around the cylindrically shaped housing10 with respect to the transverse axis of housing 10.

The lower end of each slot extends to the lower rim 12 of the housingand interrupts that rim to permit ready access to the slot.

The major portion of the slot inclines openly around the cylindricallyshaped housing 10 with respect to the transverse axis of the housing 10.The lower end portion of the slot extends axially downward until itinterrupts lower rim 12.

Housing 10 also contains a circumferential annular recess 13 adjacent torim l2. Recess 13 is interrupted by the lower end portion of the slot asit extends axially downward to rim l2. Naturally, a similar interruptionof recess 13 and rim 12 would be provided where each lower end of eachrespective slot in housing 10 is located.

Each slot has a multiplicity of notches along its inclined surfaceterminating in a final positioning notch 14 at its upper extremity. Anynumber of serrations or notches may be provided in the surface of slot11 as desired. For example, in the depicted embodiment along with uppernotch 14 four additional notches 15, 16, 17 and 18 are shown along theinclined surface of slot 11. Naturally, all slots in housing 10 wouldhave a similar notched or serrated arrangement.

The serrations are present due to the use of this type of fastener withdifferent thicknesses of panels and members to be fastened together.When thicker panels are being fastened, the fastener may lock at anintermediate position between upper notch 14 and lower notch 18 as shownin FIG. 1. Conversely, when the panels being fastened are thinner, itmay be required to rotate housing to its fullest extent until thelocking bar is seated in upper serration or notch 14. In this manner,the fastener is adaptable for use with a variety of different thicknesspanels.

A spring 19 is interposed between housing 10 and a stud element 20 andencircles hub 21 extending from the upper end of stud 20 when stud 20 ispositioned within housing 10. An appropriate recess or chamber islocated in the interior of housing 10 to receive spring 19 and the upperportion of stud member 20 including hub extension 21. A support bar 22is mounted within transverse bore 23 of substantially cylindricallyshaped stud 20. Bar 22 is slightly larger than the diameter of stud 20so that a small end portion of each end of bar 22 extends outwardly fromthe outer surface of stud 20 at approximately diametrically opposedpoints on the outer surface of stud 20. Support bar 22 may also beformed integrally with stud 20 so that the opposed transverselyextending surfaces are merely projections on the outer surface ofcylindrically shaped stud 20.

Stud element 20 is provided with a cam slot 24 at its lower end forengaging a pin 25 located in a cylindrical recess which together form areceptacle in a member or panel 26. The receptacle formed by pin 25 andits accompanying recess in panel or member 26 is dimensioned so as toreceive the forward end of stud 20.

A washer 27 is positioned about stud element 20 and both are mounted incup 28 with the lower end of stud 20 including cam surface 24 extendingthrough an opening in the lower end of cup 28. Stud 20 extendsdownwardly from cup 28 through an opening in a panel or member 29 andinto the receptacle in panel or member 26 where cam surface 24 engageswith pin 25 at which time the fastener is in position for mounting panel29 to panel or member 26. The receptacle is formed in a panel orreceptacle strip which in turn is mounted on a suitable support or frame(not shown). This is accomplished by any common type of fastening meanssuch as a screw, bolt or rivet. Naturally, other types of commonmounting means are quite acceptable for rigidly mounting strip or member26 to the support or frame.

in regard to cup 28, as shown in the drawings, its lower end is reducedin size and has a beveled flange thereon with the reduced portion andflange 30 engaging with corresponding surfaces surrounding the openingin panel 29 to mount cup 28 in fixed position with respect to the panel29.

FIG. 1 shows the fastener fully assembled and mounted on panel 29 andthe fastener assembly in locked position with panel 29 affixed 'to stripor member 26. To reach this position, several assembly steps must occur.Initially, the support bar 22 must be positioned within stud 20 asdescribed above and stud 20 must be inserted into housing 10. Theopening at the lower end of slot 11 permits ease of insertion of theprojecting ends of support bar during this assembly step. Thereafter, toretain bar 22 in slot 11, a locking ring 31 is positioned in recess 13.This locking ring forms a bottom engaging surface for the projections ofbar 22 extending outwardly from stud 20 so as to retain stud 20 withinthe housing prior to final locking engagement. Manufacturing of theassembly is facilitated in that formation of slot 1 1 is considerablyeasier to accomplish if it can be initiated at an extremity of thehousing such as lower rim 12. This is particularly true if the slot isto be formed by a milling operation. Naturally, assembly is facilitatedby the additional fact that the stud and the attached projectingportions of pin 22 can be merely inserted upward into the housing withthe pin easily sliding into position in the appropriate slot.Thereafter, it is a relatively simple operation to attach locking ring31 to the housing and in that manner retain pin 22 in slot 11. In thismanner, manufacture and assembly of the fastener is greatly facilitatedand a lower cost product results therefrom.

After locking ring 31 has been properly positioned in recess 13, theprojecting portions of pin 22 rest on the upper surface of locking ring31 in the relaxed or unlocked position. Retention in this position isassisted by the force exerted by spring 19 located in housing 20. Theforce exerted by spring 19 is sufficient to retain the exposed endportion of bar 22 in the portion of slot 1 l where it is in engagementwith locking ring 31. This position is maintained during assembly of thepanels and the fastener with respect thereto and prior to ultimatelocking of the fastener.

To reach the locked position as shown in FIG. 1 from the unlockedposition as described immediately above, the following steps areinitiated. First, the forward end of stud 20 is positioned within theprovided receptacle so that cam slot 24 engages with pin 25. Then, atool is inserted in notch 32 on the upper surface of housing 10 and theassembly formed by housing 10 and stud 20 are then freely rotated untilpin 25 reaches the closed position within cam slot 24. During thisprocess, spring 19 assists in retaining bar 22 in slot 11 so that it isin engagement with the upper surface of locking ring 31 and no tensionis applied in any portion of the fastener assembly or with respect tomembers 29 and 26.

Thereafter, further rotation of housing 10 and connected stud 20 willcause the projecting portion of support bar 22 to be displaced fromcontact with locking ring 31 and shifted along the inclined surface ofslot 11 until it becomes seated in one of the notches along slot 11. Theparticular notch where the final locking engagement occurs will bedetermined by the thickness of the panels as described above.

The fastener disclosed in the depicted embodiment is a substantiallyrigid fastener. However, there is a slight spring action present in theassembly which is produced by deformation of pin 25 when the lockingengagement is arrived at and by the fact that washer 27 is initiallycurved in configuration so that when the fastener is moved to the lockedposition the curved washer will be deformed to a substantially flatconfiguration thereby providing a slight deformation and resultantspring action. This action in combination with the deformation andspring action of pin 25 serve to resiliently react to tightening of thefastener and assist in taking up part of the load when members 29 and 26are locked together. Naturally, when the fastener is disengaged thedeformed washer 27 will substantially return to its initialconfiguration as will pin 25. It should also be kept in mind that theupper slot wall need not be serrated and can be produced with a uniformsurface without detracting from the load-carrying capacity of thefastener as shown.

The resiliency of the various interconnected members including pin 25and washer 27 as discussed above facilitates the displacement of bar 22from its relaxed position to the locked position. During the shiftingoperation, spring 19 is slightly compressed and an upward force isexerted by the forward end portion of stud 20 on pin 25. In this manner,members 29 and 26 are drawn into tight engagement with the majority ofthe force required to retain the members in fixed relationship beingsupplied by housing in engagement with the undersurface of support bar22. In this manner, it can be seen how the strength of the individualfastener employed is dependent upon the strength of the housing and thesupport bar.

To release the fastener, all that is required is a counter-rotation ofhousing 10 and stud 20 with suffrcient force applied to displace bar 22from the appropriate notch and rotated down into its initial relaxed orunlocked position in communication with the upper surface of lockingring 31. Once again, the resiliency in the fastener as discussed abovefacilitates this shifting of bar 22. Continued rotation in the samedirection of housing 10 and stud 20 will cause cam slot 24 to becomedisengaged with pin 25 once again thereby per mitting members 29 and 26to become disengaged.

It should be kept in mind that since each projection extending from stud20 as exemplified by the outwardly extending ends of support bar 22 issimilarly mounted in a slot as represented by slots 11 and 11a and therotating action to accomplish the fastening means of this structure willcause simultaneous shifting of each projection to the locked position.Additional projections and corresponding slots provide additionalsupport for the fastener means and facilitates the provision of afastener having an increased load-carrying capacity. It can be readilyseen that by having the fastening load supported by the housing wallrather than merely a spring such as spring 19 utilized in previousfastening devices, a much stronger fastener is present.

In summary, as support bar 22 shifts between the relaxed and lockedposition, it urges stud element 20 upward and thus increases the upwardforce or tension exerted on pin 25. The increase tension on pin 25 isborne by the housing wall bearing upward against support bar 22. Thisdesign permits the load-carrying capacity of the fastener to be limitedonly by the weakest part of the assembly which would most likely be theweakest part of the stud. In regard to the embodiment shown, the loadcapacity of the fastener will be about 400 pounds. This is aconsiderable improvement over previously used fasteners of this typewhere a spring such as spring 20 would carry the load and wouldgenerally not carry a load much over pounds. Furthermore, because of theincreased rigidity of the fastening engagement, less play will occurbetween the fastened members and consequently, excessive wear will bereduced about the panel opening through which the cup is inserted whenthe assembly is exposed to a large amount of vibration, particularlyover lengthy periods of time. Finally, the provision of the extendedslot and locking ring arrangement of the depicted embodiment facilitatesmanufacture and assembly of the fastener without detracting from itsload-carrying capacity. This results in a low cost product which may beeasily manufactured and produced on a large scale.

Thus, the above mentioned objects and advantages of the invention areeffectively attained.

I claim:

1. A fastener for substantially rigidly interengaging two memberscomprising:

a stud element adapted to extend through an opening in one of saidmembers and having a cam slot adapted to engage a pin on the other ofsaid members;

said stud element being rotatable between an open and closed position onthe pin;

a housing surrounding the upper portion of the stud element in rotatablerelationship therewith and being positioned on one side of the surfaceof said one member distal from said other member when said cam slot isengaged with the pin;

said housing having surfaces thereon forming a slot in the wall thereofinclined with respect to the v transverse axis of the housing;

a bar extending laterally from the stud element through the slot andengaging the slot forming surfaces of said housing;

the housing having an upper rim and a lower rim and the slot in the wallof the housing extending through at least one rim thereof so as tointerrupt the exterior surface of said rim and to facilitate insertionand removal of the bar with respect to the slot; and

means for retaining the bar in the slot so that when the pin is in theclosed position in the cam slot and the housing or stud are rotatedrelative to one another, the bar will shift in the slot from a relaxedposition to a locked position and will be supported by a portion of saidslot forming surfaces while in the locked position to thereby increasethe load carrying capacity of the fastener.

2. The invention in accordance with claim 1 wherein the means forretaining the bar in the slot includes removable locking means on thehousing.

3. The invention in accordance with claim 2 wherein the removablelocking means includes an annular recess on the circumference of saidhousing and positioned so as to intersect the slot and a removable lockring in said recess so as to close the opening to said slot and to openthe slot of said housing when removed from the recess to permit removalof the bar through said one rim of the housing.

4. The invention in accordance with claim 1 wherein the inner uppersurface of said housing is spaced from the upper end of said stud tothereby form a chamber therebetween, a spring in said chamber and beingcompressed a predetermined amount so as to bear against the uppersurface of said stud and facilitate the retention of said bar in therelaxed position in said slot.

5. The invention in accordance with claim 1 wherein a cup surrounds thehousing and stud assembly.

6. The invention in accordance with claim 1 wherein means are includedfor retaining the bar in position at intermediate positions along theinclined slot including a plurality of serrations extending along theinclined rying capacity of the fastener.

S. The invention in accordance with claim 1 wherein said housingincludes a pair of diametrically opposed slots with each slot having abar positioned therein, said bar is being simultaneously transferredbetween the relaxed and locked positions upon relative rotation betweensaid stud and said housing.

1. A fastener for substantially rigidly interengaging two memberscomprising: a stud element adapted to extend through an opening in oneof said members and having a cam slot adapted to engage a pin on theother of said members; said stud element being rotatable between an openand closed position on the pin; a housing surrounding the upper portionof the stud element in rotatable relationship therewith and beingpositioned on one side of the surface of said one member distal fromsaid other member when said cam slot is engaged with the pin; saidhousing having surfaces thereon forming a slot in the wall thereofinclined with respect to the transverse axis of the housing; a barextending laterally from the stud element through the slot and engagingthe slot forming surfaces of said housing; the housing having an upperrim and a lower rim and the slot in the wall of the housing extendingthrough at least one rim thereof so as to interrupt the exterior surfaceof said rim and to facilitate insertion and removal of the bar withrespect to the slot; and means for retaining the bar in the slot so thatwhen the pin is in the closed position in the cam slot and the housingor stud are rotated relative to one another, the bar will shift in theslot from a relaxed position to a locked position and will be supportedby a portion of said slot forming surfaces while in the locked positionto thereby increase the load carrying capacity of the fastener.
 2. Theinvention in accordance with claim 1 wherein the means for retaining thebar in the slot includes removable locking means on the housing.
 3. Theinvention in accordance with claim 2 wherein the removable locking meansincludes an annular recess on the circumference of said housing andpositioned so as to intersect the slot and a removable lock ring in saidrecess so as to close the opening to said slot and to open the slot ofsaid housing when removed from the recess to permit removal of the barthrough said one rim of the housing.
 4. The invention in accordance withclaim 1 wherein the inner upper surface of said housing is spaced fromthe upper end of said stud to thereby form a chamber therebetween, aspring in said chamber and being compressed a predetermined amount so asto bear against the upper surface of said stud and facilitate theretention of said bar in the relaxed position in said slot.
 5. Theinvention in accordance with claim 1 wherein a cup surrounds the housingand stud assembly.
 6. The invention in accordance with claim 1 whereinmeans are included for retaining the bar in position at intermediatepositions along the inclined slot including a plurality of serrationsextending along the inclined slot to permit the seating of the bar inintermediate retention positions in the inclined slot.
 7. The inventionin accordance with claim 1 wherein a washer is provided between thebottom surface of the housing and said one member, said washer beingresilient and arcuate in normal configuration and being responsive torotation between the stud and housing to facilitate movement of the barbetween the relaxed and locked positions while retaining the increasedload carrying capacity of the fastener.
 8. The invention in accordancewith claim 1 wherein said housing includes a pair of diametricallyopposed slots with each slot having a bar positioned therein, said baris being simultaneously transferred between the relaxed and lockedpositions upon relative rotation between said stud and said housing.